High speed spinning frames



April 9, 1957 A. GARDELLA EI'AL 2,787,883

HIGH SPEED smmmc FRAMES 3 Sheets-Sheet 1 Filed June 26, 1953 April 9, 1957 A. GARDELLA ETAL HIGH SPEED SPINNING FRAMES,

3 Sheets-Sheet 2 April 9, 1957 A. GARDELLA ETAL 2,787,833

HIGH SPEED SPINNING FRAMES Filed June 26, 1953 3 Sheets-Sheet 3 I I I I l I I I I I I I I I I I HIGH SPEED SPINNING FRAMES Adriano Gardella and Costantino Gardella, Genoa, Italy Application June 26, 1953, Serial No. 364,418

Claims priority, application Italy December 10, 1952 1 Claim. CI. 57-36) h This invention has for its object a high-speed spinning frame for long and coarse vegetal bastand leaf-fibres, such as hemp, linen, jute, sisal and the like.

In the mechanical spinning frames the trend is to increase in the largest possible measure the yarn-forming speed and for this purpose the twisting and coiling speed of the yarn are increased, which means to increase the spinning speed proper, to which a proportional sliverfeeding speed from the drafting device must correspond. At the same time it is required to feed to the spinning device a sliver or roving of the largest possible size, which is brought to the predetermined count of the yarn by a suitably high attenuation by drawing same.

In the spinning machines for vegetable fibres, up todate, a number of combinations of different drawing devices have been employed, without however attaining a considerable increase in the yarn production speed and without any possibility of attaining such a high or very high attenuation, as it is the case of the worsted spinning, of the spinning of synthetic fibres and the like.

For example, spinning machines for long vegetable fibres are known in which the draft unit is combined with a flyer-spinning device and is provided with means, such as small straps, guide or holding-rollers, for the sliver control within the attenuation field. Although the sliver guide and control devices during the attenuation permit of obtaining high drawing ratios and a substantially high forwarding and feeding speed of the attenuation sliver (up to 100 metres per minute) the spinning is limited by the highest revolution speed that may be reached without damage to the fiyer legs, this speed being of the order of about 4,000 R. P. M. Therefore the possibilities that are offered by the controlled drawing are not completely utilised and the yarn production cannot surpass the highest limit of about 30 metres per minute, whereby the drawing ratios are usually maintained below 1:15

and, at the most, in particular cases up to 1:30.

The same might be said for the known ring-spinning frames in which every unit of controlled drawing is combined with a ring-spinning unit. Also in this type of machines the spinning-speed, and with it the feeding speed of the sliver from the draft unit, are limited to a maximum value of about 25 to 30 metres per minute, as me maximum speed of the spinning frame permitted by the friction of the ring on the yarn cannot surpass 6,000 to 8,000 R. P. M.

Up to date the centrifugal can spinning has been almost exclusively adopted for spinning filaments produced on artificial filament spinning machines or for spinning ther very smooth fibres, such as cotton. Attempts to employ centrifugal can spinning units for spinning of coarse fibres, such as hemp, jute, flax or the like, have not given good results, and thus this very eflicient spinning system has been practically adopted only for continuous filaments, such as artificial fibres.

Furthermore, due to the irregular nature of such vegetable fibres, in order to avoid breaking and to permit the regular uncoiling and the subsequent twisting of the sliver nited States Patent consequently a successive drying of the obtained bobbins, are necessary. Anyhow, notwithstanding this, the sliver breaks frequently and the machine produces an irregular thread within limited ranges of counts that are considerably less than those required in practice, and these threads thus obtained are delivered in the form of non-compact and irregular bobbins.

The invention aims to eliminate the above outlined drawbacks and to provide a spinning frame for the said vegetable fibres which is adapted to produce, even and particularly by a dry spinning, regular threads of any count at very high production speed and while permitting high draft ratios.

The spinning frame according to the invention is characterised in a first place by the combination with a centrifugal can spinning, of a draft unit with a ratio of at least 1:30 provided with means for the sliver control during the drawing and also of a friction device arranged between the draft unit and the collecting can and adapted for controlling the thread during its twisting.

The sliver-controlling means in the draft field may comprise guiding and holding devices of any suitable kind which may be constituted, as usual, for example by a set of rollers and one or more narrow endless belts or tapes.

The device for controlling the thread beyond the draft field and during its twisting is constituted by dull-edged or smooth friction surfaces fastened to the spinning frame or preferably carried at least in part by the usual tubular reciprocating thread guide and shaped and/or arranged in such a manner as to constantly slip against the thread being formed by acting thereon from a plurality of different sides so as to exercise a smoothing action on the surface of the thread being formed, while compelling same to follow a slightly sinuous path.

The combination according to the invention of a controlled high-attenuation draft unit combined with a centrifugal can-spinning unit permits of fully utilizing the high speeds and efficiency of both units, thus obtaining high attenuations, usually substantially above 1:30, high delivery speeds for the attenuated sliver, between 30 and metres per minute, and consequently high spinning speeds, up to and beyond 20,000 R. P. M. of the coiling can.

A preferred embodiment of a high attenuation, high speed spinning frame for natural coarse fibres according to the invention is shown in the attached drawings, in which:

Figure 1 shows in elevation with parts in section a spinning frame including a high-draft unit and a frictional sliver control member according to the invention.

Figure 2 is an elevation of the draft unit.

Figure '3 shows in section the centrifugal can-spinning unit.

Figures 4 and 5 show respectively in vertical section and plan view the tubular reciprocating thread guide provided with means for controlling the thread during its twisting.

Figure 6 shows in section the lower end of a further embodiment of thread guide.

With reference to Figure l, 1 is the framework of the spinning frame carrying a set of units A for the high-attenuation drawing. Said attenuation units are provided with means for the controlling of the sliver in the draft field and are combined with an equal number of centrifugal can-spinning units B. The draft units A and the corresponding spinning units B are arranged in zig-zag formation, so as to reduce the length of the spinning frame. Between each draft unit A and the corresponding spinning unit B a device C is inserted which is adapted for frictionally controlling the thread during its formation and twisting.

Each draft unit A, particularly shown in Figure 2 comprises a pair of retaining or feeding rollers 2, 3 and a pair of delivery rollers 4, 5 constructed and operated in the usual manner, so as to obtain a high drawing or attenuation of the sliver, usually above 1:30. The slivercontrolling means in the draft field comprise a pair of narrow endless belts or tapes 6,7 spanning the roller pairs 106, 206 and 107, 207, respectively. The plane passing through the axes of the upper rollers 106 and 107 lies at rightangles to the plane N of the inner runs of the feed belts 6 and 7, while the plane passing through the axes of lower rollers 206 and 207 forms with the said plane N an angle which is different from 90. The two inner superposed runs of tapes 6 and 7 hold between them the attenuated sliver which they in part guide and in part brake. The said tape runs are pressed against each other by pressure means, such as blade springs 8 fastened by their curved upper ends to rigid frame parts 9 and acting against the tapes with their lower free ends. Thus springs 8 may swing freely towards and away from the attenuated sliver-carrying tapes and automatically alter the distance and the compression of the active runs of the tapes according to the sliver thickness. A further control of the sliver within its attenuation field is obtained by means of the fixed sliver guide 10 which is inserted between the endless tapes 6 and 7 and the delivery roller pair 4,5.

In order to permit high-speed precision spinning, a frictional control of the thread during its twisting is necessary. This is effected, as shown particularly in Figures 3 through 6, by providing the usual reciprocating tubular guide 11, Figures 1 and 3 through 6, with widely spaced radiused thread-friction means such as pins 12, ribs 115, Figure 6, restricted outlet mouths, such as shown at 13 in Figures 4 and 6 and like means, which permit a guide of the thread being spun while effecting a smoothing of its surface during its twisting, without hindering the propagation of the twisting up to the sliver delivery rolls.

In order to permit this high-speed spinning and avoid long interruption for changing the full coiling cans, these cans must be such as to permit of spinning the thread into compact and slightly conical precision bobbins and of rapidly and easily extracting such bobbins from the coiling cans, as well as of substituting full cans with empty ones.

This end is attained by providing a composite spinning unit B which comprises a suporting bell (Figures 1 and 3) rotatably supported by a cross member 101 of the framework. Bell 20 has a hollow hub 120 through which the above mentioned reciprocating thread guide 11 passes. Belt is driven through belt 23 running on pulleys 21 and 22. From the open end of bell 20 a rigid centrifugal coiling can 24 is inserted, which is tumblershaped and has a perforated bottom 124 onw hich a disk 25 bears which serves for pushing the formed bobbin out of the can. The bell and can are provided with coacting latching and unlatching means 28, 26, 27, 126, 29 adapted to be operated by automatic or semi-automatic devices, which form the subject matter of another copending application.

From the foreging it is apparent that by the combination of improved attenuation, sliver and thread-control means and by providing a composite rigid two-parts coiling can adapted to be rapidly and easily dismounted and from which a compact slightly conical precision bobbin may be easily taken out, a very slightly efiicient spinning frame, particularly adapted also for coarse fibres, has been obtained. By this frame a high attenuation of the sliver is rendered possible just by the combination of the above means.

Of course the invention is not limited to the embodiment just described and shown, but may undergo numerous changes, particularly as regards the constructive embodiment of the single units or devices of which the spining frame is composed and this without departing from the above outlined basic principle which is claimed hereinafter.

We claim:

A spinning frame for spinning long and coarse natural vegetable fibres in a single continuous step comprising in combination a high attenuation sliver-draft unit having a pair of endless tapes between whose superposed runs the sliver passes, springs arranged to press said superposed runs of the tapes one against the other permitting an attenuation of the sliver of the order of 1:30 and over, a pair of delivery rolls, and a reciprocating tubular friction member including widely spaced smooth surface thread-friction pins of round section, ribs, and restricted outlet mouths to permit a guide of the thread being spun along a sinuous path while effecting a smoothing of its surface during its twisting, without hindering the propagation of the twisting up to said sliver delivery rolls, and a centrifugal can spinning unit rotatably mounted beneath said reciprocating tubular friction member to rotate at a rapid speed filled at the outlet of said friction member, said friction pins being arranged to slightly touch the thread being formed from a plurality of different sides of said pins, whereby said thread will be engaged by relatively smooth surfaces and will not be sharply bent during twisting between the delivery rolls of the draft unit and said spinning unit.

References Cited in the file of this patent UNITED STATES PATENTS 2,052,731 Taylor Sept. 1, 1936 2,423,721 Nelson July 8, 1947 2,623,346 Lohfert et a1. Dec. 30, 1952 2,645,822 Cabana July 21, 1953 FOREIGN PATENTS 804,336 France Aug. 3, 1936 

